Timing mechanism



Sept. 14, 1943. c, so 2,329,447

TIMING MECHANISM Filed Sept. 9, 1940 5 Sheets-Sheet l &

INVENTOR. C. L. ANDERSON wvmh W W;

ATTORNEY Sept. 14, 1943. c. 1.. 'ANDERS ON 2,329,447

TIMING MECHANISM Filed Sept. 9, 1940 5 Sheets-Sheet 2 Sept. 14, 1943.

Filed Sept. 9, 1940 5 Sheets-Sheet 5 ?0 slab I 89 as U IN VEN TOR. c. L.ANDERSON ATTORNEY Sept. 14, 1943. c. L. ANDERSON 2,329,447

TIMING MECHANISM Filed Sept. 9, 1940 5 Sheets-Sheet 4 INVENTOR. 6. AANDEAfiO/V ATTORNEY p 1943. c. 1.; ANDERSON 2,329,447

TIMING MECHANISM Filed Sept. 9, 1940 5 Sheets-Sheet 5 INVENTOR. c. LANDERSON ATTORNEY Patented Sept. 14, 1943 UNITED STATES PATENT OFFICETIMING MECHANISM Carl Ludwig Anderson, Moline, Ill., assignor to EagleSignal Corporation, ,Moline, 111., a corporation of MassachusettsApplication September 9, 1940, Serial No. 356,005

9 Claims.

This invention relates to timing mechanisms and has special reference tomechanisms particularly suited to the timed operation of switches,though it should be understood that within the broad purview thereofother mechanisms besides switches may be controlled by the timingmechanisms hereof.

In the construction of timers, rotary timing members have advantagesover other types of construction due to the relatively low cost offabrication thereof and due to the compactness attainable with rotarytypes. The disadvantages of rotary types of low cost have been, first,the lack of accuracy when employing simple compact types of rotarymembers and'the resultant necessity of large timing members, and,second, the impossibility of using indicating means to show the elapsedtime within the cycle. Thus, one timer which others have unsuccessfullyattempted to sell recently was provided with an elaborate device toinsure accurate setting of the timing member but the deviation in timeof actuation at any particular setting was so great that the extremeaccuracy of the setting was needless expenditure.

It is a principal object of this invention to provide a timing mechanismwhich, with a simple arrangement of parts, increases the accuracy ofoperation many fold. It is a further object to provide a simple,low-cost, accurate timing mechanism having means for indicating at alltimes the period in the cycle of operation.

In the accompanying drawings, I have shown illustrative embodiments ofthis invention as applied to the timed actuation of switches. In thedrawings,

Fig. 1 is a front elevation of a timer in accord with this invention;

Fig. 2 is a left end elevation with a portion of the framework brokenaway, better to show the construction and arrangement of the operativeparts;

Fig. 3 is a plan of the timer shown in Fig. 1;

Fig. 4 is a vertical section substantially on the line 4-4 in Fig. 3 butwith the switches and the terminal block omitted;

Fig. 5 is apartial section substantially on the line 5-5 in Fig. 4;

Fig. 6 is a diagrammatic illustration best described as a sectionsubstantially on the plane of the line B--6.in Fig. 5;

Fig. 6a. is an edge view of a part of the structure illustrated-in Fig.6, showing certain ancillary control mechanism;

Fig. 6b is a. front elevation of the structure shown in Fig. 6a withpart of the structure removed for clearness; I

Figs. '7, 8, 9 are details of the switches and switch-operating means inreset, timing, and timed out position, respectively;

Fig. 10 is a wiring diagram of the timer showing three bridges in placebetween certain of the terminals, and with a starting switch connectedthereto;

Figs. 11 and 12 are wiring diagrams of simplified character illustratingoperation of the timer when connected as in Fig. 10;

Figs. 13, 14, and 15 are simplified wiring diagrams of the timerconnected for another of its applications, showing the operating cyclethereof;

Fig. 16 is a diagrammatic section similar to Fig. 6 but showing amodified form of the timer; and

Figs. 17 and 18 are detailededge and face views of one element of thestructure shown in Fig. 6a.

As shown in Figs. 2 and 4, a front frame plate I5 is secured in spacedrelation to rear frame plate i5 by side frame plates I! and I8. Anintermediate bearing plate I9 is secured between the plates [5 and 16parallel thereto by being secured at its right hand end to side frameplate 18 and at its left hand end to front frame plate [5 by framemembers 20 and 2|. A synchronous motor 22 is secured to the rear surfaceof the plate 19,

and is provided with a driving stub shaft 23 which extends through anopening in the plate l9 into driving engagement with the clutch member24. This clutchmember 24 comprises a shaft 25, a clutch plate 26, and ashaft 21, extending forwardly from the plate 26 into bearing engagementwith the frame plate IS. The shaft has an opening in the rear endthereof for insertion of stub shaft 23 whereby the rear end of member 24is held against lateral thrust. A second clutch member 28, comprising aclutch plate 28, gear 30, sleeve 3 I, and operating collar 32, isslidably supported on the shaft 21, with the plate 29 facing the plate26. positioned between the movable clutch member 28 and the frame platel5. Clutch operator 34, described hereinafter, bears against the rearside of operating collar to cooperate with the spring 33 in moving theclutch under electromagnetic control into. engaged and disengagedpositions.

An intermediate driving member 35 comprises a shaft 36,, which supportsnon-rotatably thereon a gear 31 in driven engagement with gear 3-0, anda gear 38, the forward side of which is concave.

An operating spring'33 is The member 35 is rotatably supported by theplates I and IS. A pin 39 is carried by a plate 48, adjustable aboutshaft 36, and extends into the concavity of the gear 38 remote from thecenter thereof for engagement with a stop 4| in the gear. A helicalrewind spring 42 is secured at its ends to plate 49 and shaft 36 inconventional manner for turning stop 4| into engagement with pin 39.This plate 48 is pivotally mounted on the shaft 36 and is provided witha set bolt 43 (see Fig. 5) to clamp the plate in adjusted position aboutthe shaft. Adjustment of plate 4| adjusts the normal or reset positionof driving member 35. i

The main timing and indicating assembl 44 involves a frictionally heldrotatably adjustable member 45 for determining the length of the timedperiod, a timing unit 46, mounted for rotation thereon and cooperationtherewith in measuring the timed interval, and an indicating member 41,also mounted for rotation on member 45, being rotatable with timingelement 46 to indicate visually the position thereof. The adjustablemember 45 involves a shaft 48, supported for rotation in frame plates l5and I9, a timing disc 49 secured to the shaft, an indicating pointer 58secured to the shaft between the plate l5 and transparency 5|, and anadjusting knob 52 secured to the shaft. A friction brake 53 is clampedon the shaft 48, and a pin 54 carried by plate |9 engages therewith, toprevent turning thereof, whereby a drag is placed upon the shaft to holdit in adjusted position.

The indicating member 41 comprises a sleeve 55 which is rotatable uponthe shaft 48. This sleeve extends from the timing disc 49 forwardlythrough the plate l5 and has a pointer 56 secured to its forward endbetween the plate I5 and the pointer 58. The sleeve 55 is provided witha shoulder in engagement with the rear surface of the plate I5, wherebythis shoulder and the rear end of shaft 48 prevent endwise movement ofthe entire timing assembly. The sleeve 55 is further provided with agear 51 secured thereto in engagement with the gear 38, whereby toindicate the position of the gear 38 at. all times during operation.

The timing unit 46 involves a sleeve 68, carried by the sleeve 55,between the gear 51 and the timing disc 49, slidable therealong. Member46 is provided with a gear 59, in engagement with the gear 38, which issufficiently wide that the two mesh in all axial positions of member 46.A timing disc 68 is secured to the rearward end of the sleeve 58, forcooperation with timing disc 49 in measuring the desired time intervalfor which the timer is adjusted.

When the timer is in reset position, the timing unit 46 is in forwardposition and the clutch is open, whereupon the spring 42 will move thegear train to a position in which the pin 39 engages the boss 4|. Inthis position. pointer 56 is in line with the zero marking on the scale.The pointer 58 is positioned with respect to the timing disc 49 so thatwhen the pointers are in alignment the boss 6| on timing disc 68 is inline with opening 62 on disc 49. The knob 52 may then be adjusted to anydesired time as indicated by the scale. Upon timing, as will beexplained herebelow, the clutch is closed, the motor driven, and thetiming unit 46 spring-pressed rearwardly. since in reset position, withthe knob set for a time interval other than zero, the boss 6| is out ofline with opening 62, the boss 6| will therefore ride upon the disc 49until it is in line with the opening, whereupon under spring pressurethe timing unit 46 will move rearwardly causing actuation of theswitching means. As the pointer 41 is driven by the same gear as thetiming unit, this pointer will indicate the movement of the timing unitand will read directly in the time elapsed since timing started.

A plurality of switch elements 63, 64, 65, 66, and 61 is pivoted on arod 68 carried by the side plates I1, l8, each switch element comprisin.an insulated pivoted arm, to the forward end of which is secured acontact member to which electrical connection is made. Each switchelement is provided with a spring 69, which bears against :the rear edgeof cradle 18, and engages the rear end of the respective switch element,whereby the forward end of each element is biased downwardly. A switchcontroller 1| is pivoted in theplates 1, I8 below the forward ends ofthe switch elements to control the relative positioning of the elementswhen allowed by the cradle 18 to be moved under action of springs 69. Inorder to move the switch controller from one of its controllingpositions to another of its positions, as below explained in connectionwith switch actuation, a pair of identical arms 12 is pivoted on a pin13 carried by frame member 2| above timing unit 46 (see Fig. 4). A pairof springs 14, supported by arm 15 carried by frame member 2|, biasesthe arm 12 clockwise, as seen in Fig. 4. A spring 16 mounted on the pin13 biases the controller 1| counterclockwise, as seen in Fig. 4, thoughthe spring 16 is considerably weaker than the springs 14, whereby thearms 12 will move the controller 1| against the action of spring 16. Thelower ends of the arms 12 are provided with enlargements which engagethe timing unit 46 to move therewith, whereby upon translation of thetiming unit rearwardly the arms turn clockwise. Upon such movement, theupper ends of the arms, which engage the switch controller 1|, will movethe controller from rear supporting position of the switch elements tothe forward supporting position.

A solenoid 11 is provided for controlling the positioning of the cradle18. The solenoid is provided with a fixed core section 18, and with amovable core section 19 pivoted thereto by pin 88. The movable coresection is connected to rod 8| through a lever arm 82 fixed to the rod8|, and through a link 83 pivotally connected to the ends of the movablecore section and the lever arm 82. A spring 84, engaging the fixed coresection and the link 83, biases the rod 8| clockwise, as seen in Fig. 2.At its farther end, as seen in Fig. 4, the rod 8| is provided with atwoended lever 85, the ends of which are provided with pins 86, 81adapted to pivotally support one end of the link 88. The upper end oflink 88 is pivotally connected by a pin 98a to the rear end of lever 89which is secured to rod 98 pivotally supported on its axis by the frameplate l8 and the internal frame member 28. A second lever 9| is securedto rod 93 and is positioned so that in raised position of link 88 itturns the arms 12 counterclockwise, as viewed in Fig. 4, moving thetiming disc 68 out of cooperative engagement with 49. In loweredposition of link 88, the lever 9| is moved to a position allowing theboss 6| to enter the opening 62. A third lever 34 is likewise secured torod 98 and cooperates with a collar 32, as heretofore described, inoperating the clutch. In position such that the timing discs are out ofcooperative engagement, lever 34 moves the clutch out of engagement.Upon actuation of rod 80 by the electrically controlled means, involvingsolenoid T1 and spring M, to

move the timing discs into operative engagement, the clutch also movesinto engagement. Therefore, with the knob turned to a position ofl ofthe zero reading so that the boss '8! is out of line with opening", thetiming operation is initiated by turning of rod 8! to engage the clutchand allow the boss 6'! to engage the. surface of 49. The disc '80 isdriven at constant, speed by the motor until the'boss isfin line withthe opening in the disc, whereupon the spring M will instantly snap thecontrol member H from one of its positions to the other.

A rod 92, also pivoted to the lever 88, effects a third function uponinitiation of timing. The upper end of rod 92 is slidably received. inthe cradle and is provided with a shoulder 93 to engage the cradle andtilt it: counterclockwise against action of spring 94, vass-icon in Fig.4, when the rod is raised. In this raised position of the cradlc, thepositions of the switch arms are controlled by the cradle. Upon loweringof the rod 32 upon initiation of the timingcyc-le, the cradle turn underaction of spring 94, whereupon the switch arms rest upon the controllermember "H, whereby their positioning isdctermlned. At the end of thetimed cycle, the member H is moved,

as described previously, whereby the positioning of the switch arms maybe shifted to a third relationship, in which positioning they are undercontrol f member 1 I.

To buffer the action of the electrical control means, involving spring84 and-solenoid 11, an arm 94a is secured to the left end of rod 8| andis pivoted to plungcr 95. arranged for sliding movement in dash pct. 96.which ispivotally carricd on pivot 91 secured to frame plate H.

An illustrativeset of switch arms is shown in Fig. 3, but it should be.understood. that extreme variation is possible in the. switchingarrangement. "The switch arms 83 and 64 comprise a single pole singlethrow switch, which maybe employed incontrclling circuits within thetimes. Accordingly, very flexible controloi this switch is provided,whereby to adapt the timer to diverse types of service. The contactmember on switch arm 64 extends over that on. switch arm 63. A

I notch 98 is provided in the forward edge of cradle 7i! below arm 64,whereby, when the cradle-is in I controlling. position, this switch maybe closed (see Fig. '7). The cradle is also provided with an openingbelow arm 64' in which a pin, 93 may be inserted, whereby this switchmay be held open when the cradle is in. controlling position (see Fig.'7). When the forward edge. of cradle 10 is lowered out of controlling.position, and the switch arms are responsive to member H in-rearwardposition (see Fig. 8), the arm 53 rests upon upward extension Ill 0 onmember'Tl, whereby the arm 64 is supported by arm '63 clear oi. bothcradle l6 and member H. In forward or timed out position of member I I,to which it is moved at the termination of the timed period (see Fig.'9) the may be omitted whereby the switch is closed in the resetposition of Fig. 7.

The remaining switch arms are in general cmployail for controllingexternal timed circuits, though or some services these switches may beemployed for simultaneously controlling both internal and externalcircuits. As shown, the arms W, B, and 61, together with theirassociated. contact members, constitute a single pole double throwswitch. Removable pins I02, I03 may be provided in the cradlelfl undereach of the arms 55 and 61, whereby in reset position each of these armsis supported. The contact member assoelated with arm 66 will then be incontact with that supported by arm 65 and out of contact with arm 61..An upward extension I04 is profvided on member II whereby in timingposition (see 8) arm 56 rests thereupon while arms 64am 6! are free tomove downward, thereby openingthe circuit between arms 65 and 66 andclosing that between arms 66 and 61. Rcarwa-rd maybe substituted for thesingle polo double throw switch, as, for instance, two single polesingle throw switches.

A terminal block I'M of insulating material is supported at the loweredge of frame plate 15. Conventional electrical conduits H1, 8 conof"the motor 22'.

terminals 108- and I [2 with solenoid TI. Conduits 1H and I22 connectthe contact elements on arms 63 and 64 with terminals I09 and H3, andconduits I 23, 1.24,. and I25 connect the contact elements on arms 55,66 and 61 with the terminals H5, no, and H5.

When the timer is arranged-as shown in Fig. m, with bridges on the pairsof terminals W'HO; I I2H3,'.and H3H4, and with the pins 98, 1162., and10! in position and link 88 connected to pin Be, the circuit diagram ofFig. 11 illu'stratcs the. circuit conditioning in reset position. Toinitiate timing, external starting switch I26 is closed, whereupon poweris communicated through the solenoid which, through connections, theoperation'of which has heretofore'becn described, moves the cradle outof controlling position, closing switch 53-64, and shifting contact arm66 from arm to arm 61, as shown in Fig. 12. Power is simultaneouslycommunicated to motor 22 through switch 6364, the solenoid 11 becoming aholding coil for switch 63-84, wherefore the starting switch I26 may bereleased. Upon the member H moving to timed out position, the circuitconditioning returns to that shown in Fig. 11. In this arrangement, thetimer automatically resets, involving turning of the cradle intocontrolling position at the termination of the timed period.

Another application, illustrating the versatility of this timer,involves the use of bridges between terminals l09l l0; and 3-! Hi, theposition ing of link 88 on pin 81, and the use of pins 99 and I83. Inthis arrangement, the switch I26 is normally open, and in timed outposition the switches 63- 64 and 56-61 are open and the switch 6566 isclosed (see Fig. 13). To reset the timer, the switch I26 is closed,whereupon all the switch arms are responsive to the cradle and allswitches are open (see Fig. 14). Upon deenergization of the solenoid byopening switch 126, spring 84 moves the remainder of the controlmechanism to engage the clutch. Atthe same time, the switches 63-64 and66-61 are closed, switch 6566 remaining open, as shown in Fig. 1.5.Termination of the timed cycle changes the circuit conditioning to thatshown in Fig. 13.

In the embodiment of the invention shown in Fig. 16, the motor andclutch assembly 24-28 is identical to that shown in Fig. 6. The gear 30engages and drives the gear 31 on shaft 36, upon which is secured a gear38' to rotate with gear 31. The shaft 43 extends from the plate I8, inwhich it is mounted for rotation, through the front plate, and isprovided with a knob 52 and pointer 53 to indicate its position. Theindicating member 61, as in the form shown in Fig. 6, comprises apointer 56 and gear 51 secured together with the gear in mesh with gear36'. The indicating member engages a shoulder on shaft 48' to preventforward movement of the shaft. The timing unit 4-5 is the same as shownin Fig. 6 except that it rotates and translates directly on shaft 38'instead of on a sleeve secured to the indicating member. The timing disc48', which cooperates with timing disc 60, is rigidly mounted upon aframe member I21, thereby making the timed out position fixed instead ofadjustable. The gear 31 meshes with a. gear I28 supported by a sleeveI29 immediately forward of the brake construction. A pin I30 extendsforwardly from the front face of gear I28 and engages a pin I3I fixed inand rotatable with shaft 48.

Accordingly, in this form, the reset position is adjustable by the knob52. A spring I32, secured to pin I3! and gear I28, returns the movableclutch member shaft 36, and gear I28 to reset position upondisengagement of the clutch.

With the clutch disengaged, and the timing discs out of cooperativeengagement, the knob 52 is adjusted to the desired position as indicatedby the scale. As the gear I28 is free to move under action of springI32, the pins I30 and I! remain in engagement and, therefore, throughthe gears 31 and 33, the timing and indicating units move with the knob.Accordingly, in reset position,

the two pointers will be in alignment. Upon actuation which engages theclutch and which moves the timing unit rearwardly to slide upon timingdisc 49, the three gears 51, 59, and I23 rotate synchronously. Rotationwill continue until the pointer 56 is in line with the zero on thescale, whereupon the timing unit will translate upon shaft 48, aspreviously described.

While in both forms of the invention, the reset and timed out positionsare relatively rotatively adjusted by the knob. in the first form it isthe timed out position which is adjusted and in the second the resetposition. In the first form, the indicating pointer 56 reads on thescale directly in the time of the cycle elapsed, while in the second thepointer reads in the time yet to elapse. It is thus to be seen that, inthe first form, the pointer starts timing from zero, in the second form,from a position in line with pointer 50, and that the motor must rotateoppositely in the two forms.

As shown in Figs. 6a and 61), this mechanism may be, and preferably is,provided with means for insuring release of the clutch when the timingunit 46 moves longitudinally of sleeve 55 carrying the boss 6| into theopening 62 of disc 43. This comprises a support I35 carried by a rigidpart of the structure, having a pivot I36, on which is pivotally mounteda lever I31, of which the end I38 engages the collar 32, and the end I39engages a fiat face of gear 58. Therefore, as the arms 12 move the unit46 longitudinally along the sleeve 56 toward disc 49, the lever I31 isrocked about its pivot I36, and end I38 pushes collar 32 forwardly,pulling clutch plate 29 out of engagement with plate 26. This frees theclutch 24 and permits rotation of clutch member 29 independently ofmotor 22. Consequently, the knob 52 may be turned to set the hand 58without rotating the rotor of the motor.

As shown in Figs. 6, 1'1, and 18, the opening 62 is preferably notuniform in dimensions, being provided with a step 62a which permits theboss 6| to enter opening 62 part way and then pause before entering allthe way. When boss 6| aligns with opening 62, then, through the pressureof springs 14 and arms 12, unit 46 will be moved until boss 6I engagesstep 62a. Also, arms 12 push support 1I forward slightly, releasingswitch support 66 ahead of 63 because of the notch 660 out in the end of66. This permits the switch 65, 66 to close momentarily before 63 isreleased from 64 by the continued rotation of element 46, the formerbeing held up by the rest I60 until the boss 6| enters all the way intothe opening 62. When this happens, the levers 12 turn about their pivot13 as far as unit 46 will permit them to turn. This pushes member 1|forward, releasing switch element 63 and permitting it to withdraw fromswitch element 64. This breaks the circuit to the timing motor 22 andcauses reset.

When the above description is considered in the light of priorconstructions, it is to be seen that this invention is limited toneither of the specific forms disclosed; wherefore, it should beunderstood that the scope of this invention is defined only by thesubjolned claims.

Having now described my invention, I claim:

1. A snap action timing mechanism, comprising cooperating timing means,one of which is rotatable and normally spring biased in one rotativedirection, one of said timing means being mounted for reciprocation,said timing means cooperating to allow reciprocation thereof in onerotative position of the rotatable timing means and to preventreciprocation in other relative positions thereof, spring means toeffect reciprocation when said elements are in said position allowingreciprocation, means for limiting spring biased movement of said springbiased timin means, said limiting means and the timing means other thansaid spring biased means being relatively adjustable to vary the degreeof movement of the spring biased means from the limited position to theposition allowing reciprocation, and chronometric driving means forrotating said r0- tatable means against the bias thereof whereby tomeasure predetermined time periods.

2. A snap action timing mechanism, comprising cooperating timing means,a shaft upon which one of said timing means is mounted for rotationthereabout and reciprocation therealong, spring means normally to biassaid rotative means in one rotative direction, spring means to bias saidrotative means in one reciprocative direction, a pair of limiting means,one of which cooperates with said rotative means to limit spring biasedrotation thereof, and the other of which in one rotative position ofsaid timing means allows spring biased reciprocation thereof and inother rotative positions thereof prevents such spring biasedreciprocation, one of said limiting means being normally fixed and theother cooperating with said shaft upon rotation of said shaft to varythe degree .of movement of said rotative means between the limitingpositions, and means for effecting rotation of said rotative meansbetween said limiting positions in the opposite direction from thatproduced by the spring means.

3. A timer comprising a shaft, a timing element mounted for rotation onand reciprocation along said shaft, a spring for biasing said timingelement for rotation in one direction, means for limiting spring biasrotation of said timing element in one direction, a timing motoroperatively connected to rotate said timing element in the oppositedirection, a second means for limiting rotation of said timing elementwhen driven by said motor, said timing element and said second limitingmeans cooperating to allow reciprocation of the timing element in aposition thereof limited by said limiting means, means for indicatingthe rotative position of the element in all positions thereof along theshaft, means to synchronize rotation of the element and of the indicatinmeans, and means to rotate the element.

4. A timer comprising a shaft fixed against longitudinal movement, atiming element mounted for rotation about and reciprocation along saidshaft, said timing element being rotatable between limiting positionsfor determining desired time in tervals, means for reciprocating saidtimin element relatively to said shaft when in one of its limitingpositions, means mounted in fixed position along said shaft for rotationwith said shaft for indicating the rotative position of said timingelement at all times, and means synchronously to rotate said timingelement and said indicating means.

5. A timer comprising a manually adjustable rotatable shaft, a timingelement mounted for relative rotation on and for reciprocation alongsaid shaft, said timing element being rotatable between limitingpositions for determining desired time intervals, means forreciprocating said timing element in one of its limiting positions, saidshaft and said timing element cooperating to effect relative adjustmentof the limiting positions upon manual adjustment of said shaft to varythe time interval, means mounted for rotation on said shaft forindicating the rotative position of said timing element at all times,and mean synchronously to rotate said timing element and said mean forindicating.

6. A timer comprising a shaft, a timing element mounted for rotation onsaid.- shaft and for reciprocation therealong, limiting meanscooperating with said timing means for limiting rotation thereof inopposite directions, indicating means mounted for rotation on said shaftfor indicating the relation rotative position of said element in allpositions thereof along said shaft, said timing element and saidindicating means each comprising a gear, and drive means for rotatingsaid timing element comprising a shaft, a gear secured to said shaftwhich engages the timing element gear in all positions of the elementalong the shaft, and a gear secured to the shaft which engages the gearof the indicating means, whereby the timing ele ment and the indicatingmeans are synchronously rotated upon rotation of said drive means.

7. In a snap action timer, the combination comprising a shaft, a pair oftiming elements carried by the shaft, one of which is secured theretoand the other of which is rotatable with respect thereto, one of saidpair being reciprocable therealong, one of said pair having a faceperpendicular to the shaft and having an opening therein, and the otherhaving a projection extending toward aid face, spring means to bias thereciprocable element toward the other element, said projection normallyriding on said face to prevent movement together of the elements, andsaid projection cooperating with said opening to allow reciprocation ofsaid reciprocable element toward the other element, means for rotatingthe rotatable element in opposite directions, coaction of saidprojection and opening limiting rotation in one direction, and means forlimiting movement in the opposite direction, said shaft being rotatablewhereby to adjust the relative positioning of the element secured to theshaft and the limiting means.

8. A switching mechanism comprising cooperating switch elements,controlling means for controlling the relative positioning of saidelements, and upon actuation to effect change of the relativepositioning of said switch elements, holding'means to hold said elementsnon-responsive to said controlling means and to control the relativepositioning of said elements when so held, a pair of timing elements,one of which is rotatable from an initial limiting position to a timedetermining position, means for reciprocating one of said elements whensaid rotatable element i in determining position, means operativelyconnecting the reciprocable element and said controlling means foractuating the latter upon reciprocation of the former, and means forreciprocating said one of said elements in the opposite direction andfor simultaneously moving said holding means to holding position.

9. In a timer, the combination comprising a shaft, a timing meansrotatable on and translatable along the shaft, spring means andchronometric means for rotatively driving said timing means in oppositedirections between limiting positions, a gear secured to said timingmeans, a face plate, indicating means positioned on the side of saidface plate opposite said timing means, a gear secured to said indicatingmeans to rotate therewith, and unitary gear means in mesh with each ofsaid gears.

CARL LUDWIG ANDERSON.

